U.S. patent application number 10/913351 was filed with the patent office on 2006-02-09 for electronic voltage polarity test probe.
This patent application is currently assigned to DESIGNTECH INTERNATIONAL, INC.. Invention is credited to Warren Bosch.
Application Number | 20060028194 10/913351 |
Document ID | / |
Family ID | 35756777 |
Filed Date | 2006-02-09 |
United States Patent
Application |
20060028194 |
Kind Code |
A1 |
Bosch; Warren |
February 9, 2006 |
ELECTRONIC VOLTAGE POLARITY TEST PROBE
Abstract
An electronic voltage polarity indicator that provides an easy
to identify indication as to whether an electrical surface being
contacted by a probe is at a positive or negative polarity. The
electronic voltage polarity indicator is particularly useable with
a 12 volt power source, and thus can find application in the
installation of equipment in vehicles, such as automobiles.
Inventors: |
Bosch; Warren; (Ashburn,
VA) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
DESIGNTECH INTERNATIONAL,
INC.
Springfield
VA
|
Family ID: |
35756777 |
Appl. No.: |
10/913351 |
Filed: |
August 9, 2004 |
Current U.S.
Class: |
324/72.5 |
Current CPC
Class: |
G01R 1/06788 20130101;
G01R 19/14 20130101 |
Class at
Publication: |
324/072.5 |
International
Class: |
G01R 31/02 20060101
G01R031/02 |
Claims
1. A test probe comprising: (a) a probe element configured to
contact an electrical surface; (b) a circuit configured to
determine if the electrical surface has a positive or negative
polarity; (c) an indicator configured to provide an indication of
the determined positive or negative polarity; (d) first and second
connectors, either one of said first and second connectors
configured to be connected to a power source and the other of said
first and second connectors configured to be connected to ground;
and (e) a light source provided adjacent to the probe element and
configured to provide a light output when the one of said first and
second connectors is connected to the power source and the other of
the first and second connectors is connected to the ground.
2. A test probe according to claim 1, wherein said circuit
comprises: (b 1) first and second resistors connected to a same
junction point.
3. A test probe according to claim 2, wherein said first connector
is connected in series with said first resistor and said second
connector is connected in series with said second resistor.
4. A test probe according to claim 2, further comprising: (d) a
power connector configured to be inserted into a cigarette lighter
receptacle, to provide power to said test probe.
5. A test probe according to claim 4, further comprising: (e) an
adaptor including (e1) a receptacle configured to receive said
power connector and (e2) first and second terminals electrically
connected to said receptacle.
6. A test probe according to claim 1, wherein said indicator
comprises: (c1) a first indication element configured to indicate
the determined positive polarity; and (c3) a second indication
element configured to indicate the determined negative
polarity.
7. A test probe according to claim 6, wherein said first indication
element includes a light emitting diode (LED) of a first color and
said second indication element includes an LED of a second
color.
8. A test probe according to claim 2, wherein said indicator
comprises: (c1) a first indication element configured to indicate
the determined positive polarity; and (c3) a second indication
element configured to indicate the determined negative
polarity.
9. A test probe according to claim 8, wherein said first indication
element includes a light emitting diode (LED) of a first color and
said second indication element includes an LED of a second
color.
10. A test probe according to claim 3, wherein said indicator
comprises: (c1) a first indication element configured to indicate
the determined positive polarity; and (c2) a second indication
element configured to indicate the determined negative
polarity.
11. A test probe according to claim 4, wherein said indicator
comprises: (c1) a first indication element configured to indicate
the determined positive polarity; and (c2) a second indication
element configured to indicate the determined negative
polarity.
12. A test probe according to claim 10, wherein said first
indication element includes a light emitting diode (LED) of a first
color and said second indication element includes an LED of a
second color.
13. A test probe according to claim 11, wherein said first
indication element includes a light emitting diode (LED) of a first
color and said second indication element includes an LED of a
second color.
14-16. (canceled)
17. A test probe comprising: (a) means for contacting an electrical
surface; (b) means for determining if the electrical surface has a
positive or negative polarity; (c) means for providing a first
indication of the determined positive or negative polarity; and (d)
first and second means for connecting, either one of said first and
second means for connecting for providing a connection to a power
source and the other of said first and second means for connecting
for providing a connection to ground; (e) means for providing a
light output, provided adjacent to the means for contacting an
electrical surface, when the one of the first and second means is
connected to the power source and the other of the first and second
means is connected to the ground.
18. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to an electronic voltage
polarity indicator that can be utilized in a vehicle environment
for testing whether an electrical surface is at a positive or
negative polarity, and to evaluate connectivity of low
impedance.
[0003] 2. Discussion of the Background
[0004] Instances often arise in which a person may want to
determine whether an electrical surface has a positive or negative
polarity. One common such instance is when installing components
into a vehicle, such as an automobile. For example, if a remote
vehicle starter or other automotive after market accessories are
being installed into an automobile, it becomes helpful to be able
to identify "dead" or "live" circuits, and instantly identified
test point as being either positive or negative in polarity
[0005] Other examples in which it may be desired to determine
whether an electrical surface has a positive or a negative polarity
is when testing door pin switches, lights, fuses, computer
inputs/outputs, and distributors.
SUMMARY OF THE INVENTION
[0006] One object of the present invention is to provide a novel
electronic voltage polarity indicator for use with vehicles that
can indicate whether a contacted electrical surface has a positive
or negative polarity, and to evaluate connectivity of low impedance
circuits.
[0007] A further object of the present invention is to provide such
a novel electronic voltage polarity indicator in a device that is
simple and safe to use, and that provides a clear and efficient
display.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A more complete appreciation of the present invention and
many of the attendant advantages thereof will be readily obtained
as the same becomes better understood by reference to the following
detailed description when considered in connection with the
accompanying drawings, wherein:
[0009] FIG. 1 shows a first embodiment of an electronic voltage
polarity indicator of the present invention from an external
view;
[0010] FIG. 2 shows circuitry included in the electronic voltage
polarity indicator of FIG. 1; and
[0011] FIG. 3 shows a second embodiment of an electronic voltage
polarity indicator of the present invention from an external
view.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] Referring now to the drawings, wherein like reference
numerals designate identical or corresponding parts throughout the
several views, and more particularly to FIG. 1 thereof, an external
view of the electronic voltage polarity indicator 10 of the present
invention is shown.
[0013] As shown in FIG. 1, the electronic voltage polarity
indicator 10 includes a handle portion 24, which can be rubberized
for an easy grip. Further, two connectors, such as alligator clips,
20, 22 are provided. Those two connectors are configured to contact
to ground and to a positive power voltage source. In most vehicle
environments that positive voltage source will be +12 volts, but
could also be +6 volts, and variations in values of the following
described circuit components can allow operation up to 50 volts
nominal.
[0014] One of the benefits of the present invention is that the
device of the present invention is fault-tolerant with respect to
the connection of the connectors 20, 22. That is, with the
structure in the present invention one of the connectors 20, 22 is
connected to the voltage source and the other of the connectors is
connected to ground, but it is irrelevant which one of the
connectors 20, 22 is connected to the voltage source and which is
connected to ground.
[0015] The connectors 20, 22 can be color coded, for example to be
black and red so that the red connector clip 20 can be connected to
a voltage source, e.g. a +12 volt power source, and the black
connector clip 22 can be connected to ground in a vehicle. However,
in this case the color coding is merely for a visual effect or for
providing a comfort level to a user, but is not needed because the
connectors 20, 22 can be connected to the voltage source and ground
in either order.
[0016] Further, the electronic voltage polarity indicator 10
includes a probe 12 formed of a conductive metal material, two
indicators 14 and 16, and an incandescent bulb 18. The incandescent
bulb 18 provides two functions. A first function is to provide an
indication when the connector clips 20, 22 are properly connected
to a ground and a voltage source to indicate that the electronic
voltage polarity indicator 10 is operating. A second function is
that the incandescent bulb 18 can operate as a small flashlight to
provide an illumination for the electronic voltage polarity
indicator 10, for example when it is used in a darkened area such
as under a dash in an automobile. Element 18 could also take the
form of other light sources, such as a white LED.
[0017] Indicators 14 and 16 in a preferred embodiment are LEDs of
two different colors that can provide an indication as to whether
the probe element 12 is contacting an electrical surface with a
positive polarity or a negative polarity. For example, the
indicator 14 can be a red LED that when lit up represents that the
probe element 12 is contacting a positive polarity electrical
surface, and the indicator 16 can be a green LED that lights up
when the probe element 12 is contacting a negative or ground
electrical surface.
[0018] FIG. 2 shows the internal control circuitry in the
electronic voltage polarity indicator 10 that provides the desired
operation and indication.
[0019] As shown in FIG. 2, connected to the probe element 12 are
the two LEDs 14, 16, which are connected in parallel to each other.
At a junction point J of those two LEDs 14, 16 a connection is made
to a circuit portion including two resistors R1, R2 and the
incandescent bulb 18.
[0020] The circuitry in FIG. 2 operates as follows.
[0021] When the power terminal 22 is properly connected to power in
the vehicle electrical system and the ground terminal 20 is
properly connected to ground in the vehicle electrical system, the
incandescent bulb 18 will glow to indicate those proper
connections. Current will also flow through resistors R1 and R2
forming a Thevinin-equivalent voltage source at the junction J
between the resistors R1 and R2. The Thevinin voltage will be half
of the automobile supply voltage, and the current may be limited by
a Thevinin-equivalent impedance of 500 ohms based on the selected
component values.
[0022] If the probe element 12 is attached to a circuit presenting
a return to ground through a low impedance, and thereby indicating
the probe element 10 contacting a point with a negative polarity,
light emitting diode 16 will be forward biased, and current will
flow through LED 16 and LED 16 will glow to provide a green
indication. The strength of the glow will be inversely related to
the impedance of the ground path, and with properly selected
component values anything less than 100 ohms will result in almost
full brightness in the LED 16. The red LED 14, in this
circumstance, will be reverse biased and will thereby not glow and
be dark.
[0023] In a contrary situation, if the probe element 12 is attached
to a point that returns to, e.g., +12 volts, i.e. an element having
a positive polarity, diode 14 will conduct and thereby light up
providing a red indication, and the green diode 16 will be
dark.
[0024] If the probe element 12 connects to a point that alternates
between power and ground as a voltage source, the LEDs 16 and 14
will glow alternately. If the frequency of alternation is high
enough the LEDs 16 and 14 may both appear to glow steadily at the
same time.
[0025] Thereby, evaluating which LED 16 or 14, or both, is glowing,
i.e., whether the green LED 16 or the red LED 14 is, glowing, or if
both are glowing, provides an indication to a user of the voltage
polarity indicator 10 whether the point the probe element 12 is
contacting a positive polarity, a negative polarity, or an
alternating power source.
[0026] As noted above one of the benefits in the present invention
is that it is irrelevant which one of the connectors 20, 22 is
connected to power or ground. That is, the circuit of FIG. 2
operates properly if connector 22 is connected to ground and
connector 20 is connected to the power, or vice versa. Further, one
of the benefits of the circuit of FIG. 2 is its simplicity in that
it allows either connection of connectors 20, 22 and requires very
few components.
[0027] With such a circuit, and as noted above, an electronic
voltage polarity indicator is provided that is simple to use, which
is inexpensive to produce, which is safe to use, and which provides
a simple to understand visual indication of a polarity of a
contacted electrical surface.
[0028] The embodiment shown in FIG. 1 utilizes specific types of
connectors 20, 22 to connect to ground and a power terminal,
respectively. A second embodiment of the present invention shown in
FIG. 3 incorporates the same structure of the probe element of FIG.
1, including the circuitry of FIG. 2, except for the connection to
a power source. In FIG. 3 instead of utilizing two connector
terminals 20, 22 a single power contact connector 26 to be plugged
into a vehicle cigarette lighter is provided. As the proble element
10 may find particular application in use in vehicle environments,
it may be helpful to utilize a power contact connector 26 for
connection into a cigarette lighter. In this device when the power
contact connector 26 is connected into a cigarette lighter the
incandescent bulb 18 will glow. Otherwise the operation in this
embodiment is the same as in the embodiment shown in FIG. 1.
[0029] Further, in this embodiment of FIG. 3 a further adaptor unit
including a receptacle portion 27 and power terminals 28 and 29 can
also be optionally provided. By utilizing the additional adaptor
unit the receptacle portion 27 can receive the power contact
connector 26 and then the terminals 28 and 29 can be connected to
ground and power as in the first embodiment of FIG. 1. That is, by
utilizing the additional adaptor unit with receptacle portion 27
and terminals 28, 29, the embodiment of FIG. 3 can be utilized in
the same manner as the embodiment of FIG. 1.
[0030] It will be obvious to those skilled in the art that numerous
additional modifications and variations of the present invention
are possible in light of the above teachings. It is therefore to be
understood that within the scope of the appended claims, the
present invention may be practiced otherwise than as specifically
described herein.
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